I really like the Vartarg ballistics, but went .221FB largely to avoid re=tooling for .20 Cal. I get 3500fps from a 24" Hart pushing 40 Vmax and virtually no recoil from a sporter weight. If I need more gun, I'll reach for my .223 AI.

If your building on a Rem action, make sure to start with a Fireball specific short action bolt to avoid ejection issues.